The Elder Scrolls V: Skyrim

Ok, so I'm about to become a Nightingale, kewl. But instead of going towards the armour stone, the characters (Brynjolf and Karliah) keep teleporting back to the start of the hall! So far i've still been able to do the quest, but i fear that later on I wont. Either way, this glitch needs fixing.

EDIT: I progressed a bit further but now I am unable to pull the chain to open the door to start the oath (Toungetwister :P) ! Brynjolf Just stands there, waiting for me to do something. I will delete this edit if it fixes its-self.

Oh, and he keeps saying the same lines over and over, which is both creepy and annoying.

I had the exact same problem. When she is supposed to go pull the chain, and you have those two dialogue options with her, choose the one that says "i don't undestand" or something like that. then exit the conversation, walk up to the door and she should walk up to you and ask you again. That worked for me. There's also another way with commands but this way is safer.